Negative reexploration for cardiac postoperative bleeding: can it be therapeutic?

Use of laboratory testing for prediction of postoperative bleeding volume in cardiovascular surgery

BACKGROUND

Coagulopathy and following massive bleeding are complications of cardiovascular surgery, particularly occurring after procedures requiring prolonged cardiopulmonary bypass (CPB). Reliable and rapid tests for coagulopathy are desirable for guiding transfusion. Measuring multiple coagulation parameters may prove useful. The purpose of this study is to determine the laboratory parameters predicting massive bleeding.

METHODS

In a prospectively collected cohort of 48 patients undergoing cardiovascular surgery, markers of coagulation and fibrinolysis were measured using automated analyzer and their correlations with bleeding volume were determined.

RESULTS

Operation time was 318 (107-654) min. CPB time was 181 (58-501) min. Bleeding volume during surgery was 2269 (174-10,607) ml. Number of transfusion units during surgery were packed red blood cells 12 (0-30) units, fresh frozen plasma 12 (0-44) units, platelets 20 (0-60) units and intraoperative autologous blood collection 669 (0-4439) ml. Post-surgery activities of coagulation factors II (FII), FV, FVII, FVIII, FIX, FX, FXI and FXII were decreased. Values of fibrinogen, antithrombin, α2 plasmin inhibitor (α2PI) and FXIII were also decreased. Values of thrombin-antithrombin complex (TAT) were increased. Values of FII, FIX, FXI and α2PI before surgery were negatively correlated with bleeding volume (FII, r = - 0.506: FIX, r = - 0.504: FXI, r = - 0.580; α2PI, r = - 0.418). Level of FIX after surgery was negatively correlated with bleeding volume (r = - 0.445) and level of TAT after surgery was positively correlated with bleeding volume (r = 0.443).

CONCLUSIONS

These results suggest that several clinical and routine laboratory parameters of coagulation were individually associated with bleeding volume during cardiovascular surgery. Determining the patterns of coagulopathy may potentially help guide transfusion during cardiovascular surgery.

Continuous postoperative pericardial flushing reduces postoperative bleeding after coronary artery bypass grafting: A randomized trial

BACKGROUND

Prolonged or excessive bleeding after cardiac surgery can lead to a broad spectrum of secondary complications. One of the underlying causes is incomplete wound drainage, with subsequent accumulation of blood and clots in the pericardium. We developed the continuous postoperative pericardial flushing (CPPF) therapy to improve wound drainage and reduce postoperative blood loss and bleeding-related complications after cardiac surgery. This study compared CPPF to standard care in patients after coronary artery bypass grafting (CABG).

METHODS

This is a single center, open label, randomized trial that enrolled patients at the Amsterdam UMC, location AMC, Amsterdam, the Netherlands. The study was registered at the 'Netherlands Trial Register', study identifier NTR5200 [1]. Adults undergoing CABG were randomly assigned to receive CPPF therapy or standard care, participants and investigators were not masked to group assignment. The primary end point was postoperative blood loss in the first 12-hours after surgery.

FINDINGS

Between the January 15, 2014 and the March 13, 2017, 169 patients were enrolled and assigned to CPPF therapy (study group; n = 83) or standard care (control group; n = 86). CPPF reduced postoperative blood loss when compared to standard care (median differences -385 ml, reduction 76% p=≤0.001), with the remark that these results are overestimated due to a measurement error in part of the study group. None of patients in the study group required reoperation for non-surgical bleeding versus 3 (4%, 95% CI -0.4% to 7.0%) in the control group. None of the patients in the study group suffered from cardiac tamponade, versus 3 (4%, 95% CI -0,4% to 7.0%) in the control group. The incremental cost-effectiveness ratio was €116.513 (95% bootstrap CI €-882.068 to €+897.278).

INTERPRETATION

The use of CPPF therapy after CABG seems to reduce bleeding and bleeding related complications. With comparable costs and no improvement in Qualty of Life (QoL), cost consideration for the implementation of CPPF is not relevant. None of the patients in the study group required re-interventions for non-surgical bleeding or acute cardiac tamponade, which underlines the proof of concept of this novel therapy.

FUNDING

This study was funded by ZonMw, the Netherlands organization for health research and development (project 837001405).

Continuous postoperative pericardial flushing method versus standard care for wound drainage after adult cardiac surgery: A randomized controlled trial

BACKGROUND

Excessive bleeding, incomplete wound drainage, and subsequent accumulation of blood and clots in the pericardium have been associated with a broad spectrum of bleeding-related complications after cardiac surgery. We developed and studied the continuous postoperative pericardial flushing (CPPF) method to improve wound drainage and reduce blood loss and bleeding-related complications.

METHODS

We conducted a single-center, open-label, ITT, randomized controlled trial at the Academic Medical Center Amstserdam. Adults undergoing cardiac surgery for non-emergent valvular or congenital heart disease (CHD) were randomly assigned (1:1) to receive CPPF method or standard care. The primary outcome was actual blood loss after 12-hour stay in the intensive care unit (ICU). Secondary outcomes included bleeding-related complications and clinical outcome after six months follow-up.

FINDINGS

Between May 2013 and February 2016, 170 patients were randomly allocated to CPPF method (study group; n = 80) or to standard care (control group; n = 90). CPPF significantly reduced blood loss after 12-hour stay in the ICU (-41%) when compared to standard care (median differences -155 ml, 95% confidence interval (CI) -310 to 0; p=≤0·001). Cardiac tamponade and reoperation for bleeding did not occur in the study group versus one and three in the control group, respectively. At discharge from hospital, patients in the study group were less likely to have pleural effusion in a surgically opened pleural cavity (22% vs. 36%; p = 0·043).

INTERPRETATION

Our study results indicate that CPPF is a safe and effective method to improve chest tube patency and reduce blood loss after cardiac surgery. Larger trials are needed to draw final conclusions concerning the effectiveness of CPPF on clinically relevant outcomes.

Active clearance of chest tubes is associated with reduced postoperative complications and costs after cardiac surgery: a propensity matched analysis

BACKGROUND

Chest tubes are routinely used to evacuate shed mediastinal blood in the critical care setting in the early hours after heart surgery. Inadequate evacuation of shed mediastinal blood due to chest tube clogging may result in retained blood around the heart and lungs after cardiac surgery. The objective of this study was to compare if active chest tube clearance reduces the incidence of retained blood complications and associated hospital resource utilization after cardiac surgery.

METHODS

Propensity matched analysis of 697 consecutive patients who underwent cardiac surgery at a single center. 302 patients served as a baseline control (Phase 0), 58 patients in a training and compliance verification period (Phase 1) and 337 were treated prospectively using active tube clearance (Phase 2). The need to drain retained blood, pleural effusions, postoperative atrial fibrillation, ICU resource utilization and hospital costs were assessed.

RESULTS

Propensity matched patients in Phase 2 had a reduced need for drainage procedures for pleural effusions (22% vs. 8.1%, p < 0.001) and reduced postoperative atrial fibrillation (37 to 25%, P = 0.011). This corresponded with fewer hours in the ICU (43.5 [24-79] vs 30 [24-49], p = < 0.001), reduced median postoperative length of stay (6 [4-8] vs 5 [4-6.25], p < 0.001) median costs reduced by $1831.45 (- 3580.52;82.38, p = 0.04) and the mean costs reduced by an average of $2696 (- 6027.59;880.93, 0.116).

CONCLUSIONS

This evidence supports the concept that efforts to actively maintain chest tube patency in early recovery is useful in improving outcomes and reducing resource utilization and costs after cardiac surgery.

TRIAL REGISTRATION

Clinicaltrial.gov, NCT02145858, Registered: May 23, 2014.

Feasibility and acceptability of continuous postoperative pericardial flushing for blood loss reduction in patients undergoing coronary artery bypass grafting

INTRODUCTION

Postoperative bleeding requires blood transfusion and surgical re-exploration that can affect the short- and long-term postoperative outcomes. Interventions that can be used in the postoperative period to reduce blood loss should be developed. Continuous postoperative pericardial flushing (CPPF) with an irrigation solution may reduce blood loss by preventing the accumulation of clots. This study examined the feasibility and acceptability of CPPF for reducing bleeding after coronary artery bypass surgery.

METHODS

This pilot study adopted a prospective and group comparison design. Between January and April 2018, 42 patients who underwent isolated coronary artery bypass surgery received CPPF from sternal closure up to 8 h postoperative. The mean actual blood loss in the CPPF group was compared to the mean of retrospectively group (n = 58). In the CPPF group, an extra infusion catheter was inserted through one of the tube incision holes and an irrigation solution (0.9% NaCl at 38 °C) was delivered to the pericardial cavity by using a volumetric pump. Safety aspects, feasibility issues, and complications were documented. The primary outcome was blood loss, and it was assessed 18 h after the surgery.

RESULTS

CPPF was successfully completed in 40 patients (95.24%). Method-related complications were not observed. Feasibility was good in this experimental setting. Blood loss was lower in the CPPF group (257.24 mL) than non-CPPF group (p < 0.001).

CONCLUSIONS

CPPF after coronary artery bypass grafting surgery is safe, effective, feasible, and acceptable. However, standardized randomized clinical trials are necessary to draw definitive conclusions.

Continuous Postoperative Pericardial Flushing: A Pilot Study on Safety, Feasibility, and Effect on Blood Loss

BACKGROUND

Prolonged or excessive blood loss is a common complication after cardiac surgery. Blood remnants and clots, remaining in the pericardial space in spite of chest tube drainage, induce high fibrinolytic activity that may contribute to bleeding complications. Continuous postoperative pericardial flushing (CPPF) with an irrigation solution may reduce blood loss by preventing the accumulation of clots. In this pilot study, the safety and feasibility of CPPF were evaluated and the effect on blood loss and other related complications was investigated.

METHODS

Between November 2011 and April 2012 twenty-one adult patients undergoing surgery for congenital heart disease (CHD) received CPPF from sternal closure up to 12 h postoperative. With an inflow Redivac drain that was inserted through one of the chest tube incision holes, an irrigation solution (NaCl 0.9% at 38 °C) was delivered to the pericardial cavity using a volume controlled flushing system. Safety aspects, feasibility issues and complications were registered. The mean actual blood loss in the CPPF group was compared to the mean of a retrospective group (n = 126).

RESULTS

CPPF was successfully completed in 20 (95.2%) patients, and no method related complications were observed. Feasibility was good in this experimental setting. Patients receiving CPPF showed a 30% (P = 0.038) decrease in mean actual blood loss 12 h postoperatively.

CONCLUSIONS

CPPF after cardiac surgery was found to be safe and feasible in this experimental setting. The clinically relevant effect on blood loss needs to be confirmed in a randomized clinical trial.

Postoperative Revision Surgery for Bleeding in a Tertiary Heart Center

We analyzed cases of re-exploration for bleeding after 19,680 open heart operations performed between January 1995 and January 2009 to determine the risk factors for mortality and morbidity. Half of the 282 patients reexplored had nonsurgical causes of bleeding. The patients were grouped according to the timing of reoperation, early reexploration being on the day of the operation. Mortality, total morbidity, and the need for transfusion of any blood product were compared between the early and late reexploration groups. Most patients (77.7%) were reexplored early. Overall mortality was 8.5% (24 patients). Mortality, total morbidity, renal, gastrointestinal, neurologic and infectious complications, and low cardiac output differed significantly between the 2 groups. Significant predictors of mortality were old age, female sex, left ventricular dysfunction, noncoronary operations, and delayed reoperation. Predictors of morbidity were old age, preoperative dialysis, tobacco use, chronic lung disease, and delayed reoperation. No factors were found to be associated with the need for transfusion.

A Betrayal of Our Handiwork: Postoperative Hemorrhage and the Need for Reoperation

Postoperative hemorrhage (PH) that requires reoperation to control bleeding represents a potentially life-threatening and avoidable complication that could have serious implications for recovery. All surgical patients were reviewed who developed PH and required reoperation for control of hemorrhage over a 12-year period, to examine contributing factors possibly related to surgeon misadventure. Of 89,663 operations during this period, there were 1,031 patients (1.2%) who developed PH. Of these, 36 patients required reoperation for control of PH (0.04%), including, general surgery (17), otolaryngologic (9), cardiovascular (9), and gynecologic (1) patients. In 27 general, cardiovascular, and gynecologic patients (29 reoperations), the age ranged from 6 to 91 years. Almost one-half of patients (56%) developing PH were on preoperative anticoagulation. Estimated operative blood loss (EBL) was moderate (EBL = 100-500 mL, 48%). Most patients were normothermic (80%) and normotensive (93%) intraoperatively. The decision to reoperate was not made for at least 8 hours in 55 per cent of patients. At reoperation 10/29 patients were hypotensive. In 20/36 patients (56%) the reoperation note did not identify a single source of bleeding. PH is a distinctly uncommon complication of surgery and often not due to obvious surgeon misadventure. Reoperation for PH is even rarer and embarked upon with reluctance, frequently not yielding a discernible cause for hemorrhage.

Coagulation and fibrinolytic protein kinetics in cardiopulmonary bypass

The development of Cardiopulmonary Bypass (CPB) catopulted the field of cardiothoracic surgery into a new dimension--one that changed the lives of individuals with congenital and acquired heart disease worldwide. Despite its contributions, CPB has clear limitations and creates unique challenges for clinicians and patients alike, stemming from profound hemostatic pertubations and accompanying risk for bleeding and possibly thrombotic complications.

Beyond cell based models of coagulation: analyses of coagulation with clot "lifespan" resistance-time relationships

Cell based models of coagulation (CBM) have provided mechanistic insight into numerous hematological issues for nearly two decades. This review discusses another coagulation model system--the clot lifespan model (CLSM)--that has been designed to compliment the CBM-based approach to elucidating the mechanisms responsible for a variety of hemostatic disorders/phenomena. The CLSM is a thrombelastograph-based approach that utilizes a standardized clotting stimulus (e.g., celite, tissue factor) and a fibrinolytic stimulus (e.g., tissue type plasminogen activator) to assess clot growth and disintegration via changes in clot resistance. The CLSM utilizes parametric, elastic modulus-based parameters to document these phenomena. The CLSM has recently been employed to discern the effects of protamine and hydroxyethyl starch on key fibrinolytic-antifibrinolytic protein interactions, as well as demonstrating differences in fibrinolytic kinetics dependent on whether contact pathway proteins or tissue factor is used to initiate coagulation. The CLSM is presently being utilized to investigate the effects of ventricular assist device placement on fibrinolysis, and it is anticipated that this model system will be employed in both basic science and clinical investigations in the future.

Management approaches to platelet-related microvascular bleeding in cardiothoracic surgery

Patients undergoing cardiac surgery with cardiopulmonary bypass are at increased risk for microvascular bleeding that requires perioperative transfusion of blood components. Platelet-related defects have been shown to be the most important hemostatic abnormality in this setting. The exact association between preoperative use of potent platelet inhibitors and either bleeding or transfusion in patients undergoing cardiac surgical procedures is currently being defined. Laboratory evaluation of platelets and coagulation factors can facilitate the optimal administration of pharmacologic and transfusion-based therapy. However, their turnaround time makes laboratory-based methods impractical for concurrent management of surgical patients, which has led many investigators to study the role of point-of-care coagulation tests in this setting. Use of point-of-care tests of hemostatic function can optimize the management of excessive bleeding and reduce transfusion. Accordingly, point-of-care tests that assess platelet function may also identify patients at risk for acquired, platelet-related bleeding. The ability to reduce the unnecessary use of blood products and to decrease operative time or reexploration rates has important consequences for blood inventory, blood costs, and overall health care costs.

Low-dose aprotinin is ineffective to treat excessive bleeding after cardiopulmonary bypass

BACKGROUND

Uncontrolled clinical experience at our institution suggested that low-dose aprotinin could control excessive bleeding after cardiopulmonary bypass (CPB). A randomized clinical trial was conducted to determine the efficacy of low-dose aprotinin in the treatment of hemorrhage after cardiac surgery.

METHODS

One hundred seventy-one patients undergoing cardiac surgery with CPB were included. Forty-four patients (26%) bled significantly in the intensive care unit (>100 mL/h) and received either aprotinin (200,000 KIU bolus + 100,000 KIU/h for 8 hours) or placebo in addition to our standard management of excessive bleeding.

RESULTS

Median bleeding before study drug administration was not different between aprotinin (200 mL) and placebo (212.5 mL) groups. Bleeding decreased significantly with time and similarly in both groups. Ninety-five percent of patients required transfusions in both groups. Median blood products transfused were 13 and 8 units per patient in the aprotinin and placebo groups respectively (p = NS).

CONCLUSIONS

Routine administration of low-dose aprotinin as part of the treatment protocol to control hemorrhage after CPB does not reduce bleeding or transfusion requirements and, therefore, cannot be recommended.